Hi!

I got some STP (STEP) files from client. (nothing fancy or too complicated) and i open them just fine in MOI, works great. Then i saved model directly from MOI again into STP format and to my suprise filesize is now a lot bigger ?

File I got is 1.3MB, when i save it from MOI the it is 45MB (that's like 35x bigger/increase) ? I suppose other app used some kind of LWZ/ZIP compression (I don't know what's the app they made model in) so i wonder do we have some file compression options/settings in MOI ?

Doesn't seem as big deal (HDD space is cheap nowdays) but since i work over network/NAS when files become big (this one is easy, others go 200+ MB) i loose time for network traffic so i'd like to minimize that if possible.

thanks in advance

Hi Lewis, as far as I know STP files can only be plain text files and cannot contain any ZIP type compression in them, so it's not possible to have settings for that.

The file size increase is probably due to expansion of instances into individual objects - MoI does not currently have any instancing mechanism in it so if the STP file contains a lot of repeated instanced data, at import time into MoI those instance copies are converted into full copied objects and that's probably what resulted in the file size increase.

I do want to add an instancing mechanism into MoI in the future to preserve them and avoid this from happening.

- Michael

Thank you for answer Michael. Although I'm pretty sure in this case it's not instancing since my target model i got has no repetitive parts. It's single Tablet PC with interior and chips are all different size/rotation and from exterior there is only glass, case and several buttons and all on different position size so it's probably just some sort of compression thing or whatever they did to make file so small.

Thanks

Hi Lewis, well different positions can definitely be handled by instancing...

But another possible thing is that often times STP files will only contain the 3D curves for trimming boundaries, and MoI uses a combination of both 3D edges and UV space edges for every trimming boundary edge. It could be possible that those newly created UV trim edges are what increases your file size.

But that's just another guess, if you want to send me the file at moi@moi3d.com (you'll need to send a link to a file sharing service like dropbox or similar), I could try to take a look and possibly give a more definitive answer.

- Michael

Thanks for great support Michael. Sadly i can't send model since it's strict NDA product so far. But maybe one day when it's released :).